Air cleaning intake for gas turbines and other internal-combustion engines



June 10, 1952 ms 2,600,302

AIR CLEANING INTAKE FOR GAS TURBINE-S AND OTHER INTERNAL-COMBUSTION ENGINES Filed Sept. 7, 1949 CUMPPAS Inventor Jar/N Knvss LL A ltorneys Patented June 10, 1952 UNITED STATES ATENT OFFICE AIR CLEANING INTAKE FOR GAS TURBINES AND OTHER INTERNAL-COMBUSTION EN- GINES British company Application September 7, 1949, Serial No. 114,329 In Great Britain October 21, 1948 '7 Claims. 1 This invention relates to air intakes for gas turbines and other internal combustion engines of the kind including an annular air inlet passage which, in the case of a combustion turbine, leads to the first stage of the air compressor and, in the case of an internal combustion engine driving a propeller, may surround the propeller shaft and be formed in a so-called ducted spinner in which the boss of the propeller is housed.

The object of the invention is to provide an improved air intake of the kind in question which will provide a forwardly facing air inlet orifice so as to take advantage of the ram effect of the passage through the air of an aircraft or other vehicle on which the engine is used in increasing the pressure at which air is supplied to the engine and will yet tend to prevent the formation of ice in the parts of the air intake assembly through which air fiows to the engine and/or the entry into the engine of particles of water, ice or other foreign matter which may be present in the air stream entering the inlet orifice.

In gas turbines used for jet populsion of aircraft and other vehicles without the use of a propeller the air inlet passage frequently comprises an air inlet orifice of substantially circular cross-section leading directly to an annular air inlet passage of larger external diameter than the air inlet orifice, the centre of the annulus being filled by a bullet-shaped streamlined body. When such a turbine is used in conjunction with a propeller and also where other types of internal combustion engine employing propellers are used, an air inlet of similar form may be employed by the use of a so-called ducted spinner, in which case the central streamlined body surrounds and projects in front of the propeller boss and the rear end of the ducted spinner com,- municates with a stationary annular continuation of the annular inlet passage in the spinner. The invention is applicable to both types of arrangement referred to above.

An air intake for a combustion turbine or other internal combustion engine according to the present invention comprises an annular air intake passage communicating at its inlet end directly with an air inlet orifice situated directly in front or upstream of the annular air intake passage, said air inlet orifice having a marginal contour which, viewed from up-stream in the direction of air entry, lies wholly within the inner circumference of the annular air inlet passage, and a receptacle for foreign matter situated within the inner circumferential wallof the annular air intake passage and having an inlet opening for foreign matter lying directly behind or down-stream of the air inlet orifice and of at least equal cross-section to the inlet orifice.

In most arrangements the air inlet orifice will be substantially circular in cross-section while the inlet opening to the receptacle will similarly be circular and. of somewhat larger diameter than the air inlet orifice.

Further in any case one or more discharge openings or passages preferably lead from a point in the receptacle adjacent to its rear or downstream end through which a quantity of air can fiow continuously or intermittently to carry away with it foreign matter which may tend to collect in the receptacle. The dimensions of the one or more discharge openings or passages may vary according to requirements, but will generally be the minimum necessary to achieve their purpose so that as little aspossible of the air entering through the inlet orifice escapes through the receptacle.

The invention may be carried into practice in various ways but one construction according to the invention and a modification thereof are illustrated somewhat diagrammatically by way of example in the accompanying drawing, in which Figure 1 is a diagrammatic side elevation of one construction according to the invention, and

Figure 2 is a similar view to Figure 1 showing the modification.

In the constructions illustrated the apparatus comprises an annular air entry, indicated at A, to the axial flow compressor B of a gas turbine system, this annular air entry communicating directly with the rear or down-stream end of an annular air intake passage C formed between inner and outer circumferential walls C C and extending forwardly up-stream from the entry A to a central circular forwardly facing air intake orifice D.

The air inlet orifice D is of considerably smaller diameter than the outside diameter of the air entry A to the compressor B and of the air inlet passage C and is of somewhat smaller diameter than the internal diameter of the air entry A, the diameter of the inlet orifice D being, in the construction shown, somewhat less than half the external diameter of the air entry A and about two-thirds of the internal diameter of the air entry.A.

1 As willbe-seen the outer wall C of the intake passage. 0 merges at its tip-stream end into the wall. of the air intake'orifice D and the diameter of this wall increases progressively in the downstream direction from the air intake orifice to a part adjacent to the air entry A where it is approximately cylindrical.

The inner wall of the annular airlintake passage C terminates at Ean appreciable distance behind or down-stream of the air intake orifice D and has a diameter which starts as slightly greater than the diameter of the intake orifice D and increases progressively in the down stream direction from its forward end to arear section C which is substantially cylindrical.

Formed within and coaxial with -.the.inner circumferential wall C is a substantially :cylindrical receptacle F, the forward or up-stream end of which is open and is connected directly at ,E to the forward end of the wall C so that-this .open end lies directly behind and down-stream of the orifice D and has a diameter which is somewhat greater than the diameter of the orifice D.

The rear or down-streamend-of the receptacle F is closed by a wall F except for a discharge passage G through which alimited :fiowbfzair can take placecontinuously, this passage'G'passing across the air inlet passage :0 through the portion 0 of the outer wallzthereof-and eventually through the wall of a :hollow :streamlined body H which encloses the turbine system in known manner.

It will be seen that the front or'upest-reamlend of the wall C is connected'to .andiconveniently formed continuous with'the .wall-of the :hollow streamlined body H customarily surrounding .aircraft propulsion enginesand whichthus extends backwards with respectto the direction-of movement thereof outsidetheair inletpassageC-and the compressor B and ;is spaced therefrom .in known manner.

Between the rear or :dowmstream end :of :the receptacle F and thefront OI'illD-IStlIGSHl end of the compressor B is a space-J into which .hotrair or gas is fed continuously from some suitable part of the power plant,.ior-example from ;the ietor exhaust pipe, through :a series ofipassageszK-extending radially across the rrearrpartzof the air inlet passage C and communicating attheirrouter ends with an annularimaniioldttube K atcwhich the hot gas is fed through a pipe K As will be seen the circumferential wall 5' of the receptacle IF, .the innerand outer-walls .C and C ofthe air intake passageiand a forward part H of the outer streamlined wall Hareiformed double with a space between :the TtWO zlayers through which gas can be caused-to flow.

In the constructionshownintFigurel the hot.

gas delivered into thespaceJ isarrangedztofiow forwardly with respectto the streamlined'rbody H through the double wall F then rearwardly through the double wall Cl, the;rearrend;of:the gas space in which communicatesthrough-aseries of radial passages L with-therrear endzof the space between the two layers of thefrloublexwall C so that the hot gasfiowsjfromxthe. rear end of the double wall C throughthemassages L;into the double wall C ;forwardlythroughathis double walland then rearwardly throughathefiouble-wall H to an annular exit indicated at-l-l Heat is thereby .conducted' to :the: doublerwalls in question by the hot gas.

In the alternative construction :shown HIE-igure 2 hot gas-flows from the space IJ forwardly through the double wall F then rearwardly through the double wallzG 1170- exits thaair intake .xpassage r. C. .Inaddition. hot gas fiows:di-

rectly: from the. space J ithrouglratseriesrof radial I passages L somewhat resembling the passages L in Figure 1, into the rear end of the double wall C from which the hot gas flows forwardly through the double wall C then rearwardly through the double wall H and through the exits H It will be seen that in-each of the-constructions illustrated the air entering the air inlet orifice D will, immediately after entry, be deflected radially outwards in order to enter the annular air-inlet passage :0, while heavy particles, for example of wateror solid foreign matter, will be carried by their momentum into the receptacle F :so that the .air entering the turbine through :the inlet A tends to be substantially free from water orsolid particles. Any water or solid particles received by the receptacle F will tend to befed-away continuously through the passage G into the atmosphere surrounding the streamlined body H.

In addition, under idling conditions, or at all times, the feeding of hot gas throughtherpipeK into the space J and thence'throughthe double walls as described above willresult-inheatbeing continuously supplied to the :wallsF and F of the receptacle F, the wall of the'airiinlet orifice D and the walls C C of the .aininletpassage C and the forward part H of the streamlined body H, thus assisting in the prevention of ice accumulation on these parts. Moreover under icing conditions, ice particles entering or tendingitoform in the receptacle Fiwill belmeltedand drained away as water through the passage G.

In some casesmeans maybe.v provided for controlling the passage G so that insteadof being open continuously it can be opened intermittently to permit escape of matterwhichmay have accumulated in the receptacleF.

What I claim as my invention .and desire to secure by Letters Patent is:

1. An air intake assemblyfor agas turbinesystem comprising anair intakeorifice an annular air intake passage having inner and outercircummerential walls and lying wholly downstream ofsaid orifice in relationto the direction of flow of air through said orifice and withlits inlet-end facing generally upstream inrelationto thedirection of flow of air through said orifice and communicating at its inlet enddirectly-withsaid orifice,-the marginal contour. of-said orifice lying wholly within the circumference'ofsaid inner circumferential wall of said annular passage when viewed inthe direction. of airr'fiowthrough saidiorifice, and a receptacle for foreign matter situated within the said inner circumferential wall of said air intake passage, with an inlet opening situated on the upstream side-of thereceptacle and directly downstream of and facing'said airintake orifice so as to catch foreign matter entering the orifice.

2. An air inlet. assembly as claimed inclaiml, inwhich the airintake orifice is;approximately circular in cross-section and has .a diameter which is less than the. diameter. of the inlet openinginto the receptaclesforioreign matter.

.3. An air. intake assembly as claimed in claim12, in which said receptacle for .foreign matter :is provided .with .an outlet passage leading :from :it adjacent to its downstream gen'd through which flow can takeplace-so as ,to-enable foreignmatter which maylaccumulate in thereceptacleito be:.discharged.

I 4. An air intake assemblyas claimed intclaim 3 in 1 which .the .receptacle is surrounded at :least partially by. a heating. space. and meansaraprovided for feedingv hot gas continuously :through said space from a part of the gas turbine system.

5. An air intake assembly as claimed in claim 4, in which said receptacle comprises double circumferential walls forming an annular surrounding enclosed space, and said inner circumferential wall of said annular air intake passage similarly comprises double circumferential walls forming a second annular enclosed space, communicating directly with the first enclosed space adjacent the rim of the inlet opening of said receptacle, and comprising means for continuously delivering hot gas from a part of said gas turbine system to said annular enclosed spaces.

6. An air inlet assembly as claimed in claim 1, in which said receptacle for foreign matter vis provided with an outlet passage leading from it adjacent to its downstream end through which flow can take place to enable foreign matter which may accumulate in the receptacle to be discharged.

'7. An air inlet assembly as claimed in claim 1,

in which the wall of the receptacle is surrounded at least partially by a heating space and means are provided for feeding hot gas continuously through said space from a part of the gas turbine system.

JOHN KINSELLA.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

